So, I just bought a used pair of Yamaha HS-50D monitors last night, and I already love them. They're a huge step up from the entry-level Edirol turds I've been using for the past million years.

That said, I am getting a lot of noise from what I know should be nearly silent monitors. It sounds like radio interference (kind of like the sound a cell phone makes when interfering with a signal), but there is a little white noise in there as well.

The HS-50s do have balanced XLR inputs, but alas, I have no XLR outputs on my mixer. So I'm relegated to using the 1/4" input. Can anyone suggest the best cables to use in connecting my mixer to these monitors if my goal is noise reduction?

I posted this in the Low End Theory forum. I had the same issue. Bought a ground loop isolator from The Source for 15-20$, plugged that in and voilà. No more noise.

Sounds awesome, just checked it out. I am seeing a lot of different options as far as input/outputs go though, can you explain what exactly you got? I've never used a ground loop isolator before, so I'm shooting in the dark. Also, does this take away from the audio signal at all?

Sounds awesome, just checked it out. I am seeing a lot of different options as far as input/outputs go though, can you explain what exactly you got? I've never used a ground loop isolator before, so I'm shooting in the dark. Also, does this take away from the audio signal at all?

Search for ground loop isolator at Radioshack, they usually have some RCA plugs so you'll need adaptors. I didn't find that it took away from the signal. It's quiet now so even if it did a little, it's still better than the noise it had before.

Search for ground loop isolator at Radioshack, they usually have some RCA plugs so you'll need adaptors. I didn't find that it took away from the signal. It's quiet now so even if it did a little, it's still better than the noise it had before.

I totally understand the trade-off, but using converters would probably make me super paranoid that I wasn't getting a clean signal. I think what I'll do is invest in some high end patch cables to go between my mixer and HS-50s, and if I'm still getting the interference, I'll take your route. Thanks much either way!

Try putting a two prong adaptor on each of the three prong cords coming out of the monitors. I know it sounds weird, but it worked for me.

Johnny, are you still alive?
Power ground is there for safety....
Sure, cutting the power ground could kill the groundloop, but it might also kill you.

OP, this sounds like a typical groundloop.
Does your mixer have balanced outputs. (Brand/model?)
If so, balanced TRS leads will likely fix the problem.
AFAIK, these speakers also take TRS jack plugs.
Or use TRS-XLR leads.
Leo..

Surge protectors (MOVs) are used to kill high voltage power spikes. Surge protector - Wikipedia, the free encyclopedia
Mains filters (a combination of coils and capacitors) are used to suppress mains RF noises.
One, or the other, or both, can be used in surge protector power strips.
They are almost always already part of a switchmode power supply.
This has NOTHING to do with GROUNDLOOPS.
Groundloops are made by yourself by using the wrong interconnect cables.
Leo..

The mains ground wire is used to ground the outside metal of an appliance.
Think toaster, washing machine, but also the metal heatsink/XLR plug of a speakerbox.
In the case of a fault inside your speaker, e.g a blown mains filter capacitor, or a loose wire, mains voltage could come in contact with the metal casing.
This will make the whole outside and everything else connected to it live.
The ground wire will safely short this to ground.
Leo..

Hi.
By grounloop isolator, do you mean audio transformers between the two devices. 1:1 transformers with RCA connectors.
This works to break the groundloop, but it also degrades the sound.
Ok for consumer audio, but not for high end monitoring.
Better to understand where/how the groundloop is created, and fix it there.
Post your exact setup if you want help.
Leo..

Have a pair in another space w/ the sub. You need to plug them into a power conditioner. The noise is coming from your outlets and transmitted thru your speakers. Unless you have clean power your gunna have problems. You might not hear the dirty power on other speaker /devices but you will with the yamahas. Besides a decent power conditioner will clean up noise elsware in your studio. Just my experience since we first had them hooked up to a power strip conected to the outlet for test purpose's. We heard the hash and ran them tru the studio rack. Problem solved. Just my experience with them. Not bad speakers. Oh we keep computers, laptops and other non tracking powered devices seperate from our tracking gear. By seperated I mean different racks and power conditioners.

Last edited by SammyDD; 20th December 2012 at 02:21 AM..
Reason: seperation

I always hesitate telling people what to buy. I just offer what works for me. The power coming into your home or office has alot of noise from other devices connected all along the system. I'm not an expert on any of this and maybe someone who is can elaborate. However, I have always used a power conditioner when dealing with audio of any kind. Furman is good plus there are many others. If your guuna get serious about your sound then you should start with the power you use to run your studio items. Also computers and other like devices are noisey and we try and keep them out of the loop and as seperate as we can. Anything that throws off a signal is gunna effect something that has the ability to pick up frequencies. Again, I'm no expert but a power conditioner is a useful thing to have in the studio.

Plug everything into the same strip & into the same outlet. Monitors, mixer, computer, rack, everything. If any one thing is on a different circuit, there can be a difference in ground potential and all kinds of ugly can happen.

If that by itself doesn't fix it, try removing the mixer from the chain -- just plug your audio interface (or whatever) right into the speakers. Then add stuff back in one piece at a time until you find the culprit.

If that doesn't fix it, i don't know.. move? I've never used one of those isolators, even in my 100 year old house with its 40 year old wiring. just follow some simple rules, use decent interconnect cables, balanced wherever you can, and you won't have RF or 60hz problems. If your mixer has balanced outs, XLR to TRS will be the best thing to do. And yes, quad cables are a specialized thing, not really for this application.

If you *really* can't get it fixed, then you can probably at least mitigate it a bit with gain staging, i.e. turn your monitors down and turn your mixer up. Make sure your audio interface is set correctly for balanced/unbalanced too.

On one surge protecting powerbar I have the iMac and the monitors. On another power bar I have the Mackie MCU, API lunchbox, DBX160X, ISA one. I tried on another outlet, had same white noise.

Not clear what A/D D/A converter you're using.
Please explain the D/A > speaker input leads, including adapters etc that you are using now.

And again, power conditioners remove mains crap, but do NOTHING for a ground loop, unless they use transformers or some sort of groundlift.
"Power conditioner" means nothing to me, unless I know what's inside.

So good luck with everything. Like I said We Have Them and Use Them in another setup. They had the noise your talking about but we Solved the Problem by pluging them into our studio rack which has a POWER CONDITIONER and is SEPERATE from the COMPUTER. This is your solution. Give it a try it worked for us.

Hi SammyDD
Not trying to argue with you.
Maybe your crap was not caused by a groundloop.
Or maybe your power conditioners use the proper technology.
I always like to understand what's causing the noises before I try to fix it.
That is not always easy in a bigger setup.
Leo..

So you're sure the headphones are 100% clean, and you got hash on your monitors, even with balanced TRS-TRS leads to the speakers.
And you can fix this hash with inline transformers..
This is very uncommon.
I would try plugging the two monitors in a seperate powerstrip, and plug that into a ebtech hum-ex ground isolator.http://www.ebtechaudio.com/humxdes.html
If you are on US power...
One last question. Is the hash also there (with balanced TRS-TRS monitor leads) if you unplug the XLR INPUT leads from the Duet?
So only Computer > Duet > Monitors (I assume the Duet is only USB bus powered).
Leo..

edit: If you have TRS-XLR cables between interface and monitors, you could try lifting the ground pin(1) wires inside the XLR plugs.

Hi solarplexus311.
Please post your findings with the hum-ex.
First use it on the monitors (two! of them in a powerstrip).
If that doesn't work, use the hum-ex on the imac.
I assume here that nothing else is connected to the imac that could give groundloops, like a network cable.
Leo..

Hi solarplexus311.
Please post your findings with the hum-ex.
First use it on the monitors (two! of them in a powerstrip).
If that doesn't work, use the hum-ex on the imac.
I assume here that nothing else is connected to the imac that could give groundloops, like a network cable.
Leo..